Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Evaluation of Geotechnical Properties in Weak Soils Stabilized by Combined Application of Lime, Fly-Ash, Geopolymer, and Scrap Tires Evaluation of Geotechnical Properties in Weak Soils Stabilized by Combined Application of Lime, Fly-Ash, Geopolymer, and Scrap Tires 911 938 5799 10.22060/ceej.2025.22660.8024 FA MEHRDAD AMINIZADEH Ph. D. candidate, Department of Civil Engineering, Estahban Branch, Islamic Azad University, Estahban, Iran, Mehdi Mokhberi Associated prof., Department of Civil Engineering, Islamic Azad University, Estahban Branch 0000-0002-8722-2612 Mehdi Momeni Roghabadi Department of Civil Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran Journal Article 2023 09 15 A lot of civil engineering projects must be constructed on weak or problematic soils. In some cases, road subgrades or building foundations often consist of soft clays or windblown sands that necessitate soil improvement for usability. Lime has served as a conventional stabilizer, with combined lime-fly ash applications further enhancing soil cohesion. These traditional materials are widely used in desert and arid environments to mitigate foundation settlement and strengthen road subgrades. Recently, scrap tires have gained traction in soil stabilization due to their reduced environmental impact. However, the synergistic effects of rubber components (crumb rubber powder and rubber fibers) with traditional stabilizers remain unexplored, primarily because rubber incorporation weakens lime mortar strength. This study examines the influence of combined crumb rubber powder (0–30% at 4% increments) and rubber fibers (0–2%: 0%, 1%, 1.5%, 2%) on the mechanical properties of lime-treated and lime-fly ash-stabilized soils. Results indicate that crumb rubber powder slightly reduces the compressive strength of stabilized soil, whereas rubber fibers significantly improve compressive strength, ductility, failure strain, elastic modulus, bulk modulus, resilience modulus, and shear strength across all curing periods. Furthermore, the optimal combination is achieved with 12% crumb rubber and 1% rubber fibers added to lime-fly ash mixtures. A lot of civil engineering projects must be constructed on weak or problematic soils. In some cases, road subgrades or building foundations often consist of soft clays or windblown sands that necessitate soil improvement for usability. Lime has served as a conventional stabilizer, with combined lime-fly ash applications further enhancing soil cohesion. These traditional materials are widely used in desert and arid environments to mitigate foundation settlement and strengthen road subgrades. Recently, scrap tires have gained traction in soil stabilization due to their reduced environmental impact. However, the synergistic effects of rubber components (crumb rubber powder and rubber fibers) with traditional stabilizers remain unexplored, primarily because rubber incorporation weakens lime mortar strength. This study examines the influence of combined crumb rubber powder (0–30% at 4% increments) and rubber fibers (0–2%: 0%, 1%, 1.5%, 2%) on the mechanical properties of lime-treated and lime-fly ash-stabilized soils. Results indicate that crumb rubber powder slightly reduces the compressive strength of stabilized soil, whereas rubber fibers significantly improve compressive strength, ductility, failure strain, elastic modulus, bulk modulus, resilience modulus, and shear strength across all curing periods. Furthermore, the optimal combination is achieved with 12% crumb rubber and 1% rubber fibers added to lime-fly ash mixtures.

https://ceej.aut.ac.ir/article_5799_de01d76e793fec3fba32f4401a45fb20.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Green Synthesis of Silver Nanoparticles: a Review of the Methods and Antioxidant Properties of Nanoparticles Green Synthesis of Silver Nanoparticles: a Review of the Methods and Antioxidant Properties of Nanoparticles 939 972 5800 10.22060/ceej.2025.23714.8202 FA Meysam Naseri Phd student - Faculty of Mining Engineering - Amir Kabir University of Technology Mehdi Irannajad Amirkabir University of Technology 0000-0002-5469-084X Akbar Mehdilo Assistant Professor, Faculty of Mining Engineering, Amirkabir University of Technology Raheleh Khosravi N Isian Pouyeshgar NanoSabz Company, Isfahan, Iran Journal Article 2024 12 04 Silver nanoparticles (AgNPs) are well-known for their significant antioxidant properties due to their ability to scavenge and neutralize free radicals and reactive oxygen species (ROS). This characteristic has led to their widespread application in cosmetic, hygienic, and pharmaceutical products. Various synthesis approaches exist for producing silver nanoparticles, broadly categorized into top-down and bottom-up methods. The top-down approaches include mechanical activation, lithography, and other physical methods, whereas bottom-up approaches encompass hydrothermal synthesis, redox reactions, sol-gel processes, and green synthesis techniques. Among these, green synthesis has gained considerable attention because of its environmental friendliness, cost-effectiveness, and sustainability. Green synthesis utilizes natural sources such as plants, algae, fungi, and bacteria as reducing and stabilizing agents. This study aims to identify the most suitable green synthesis method for producing silver nanoparticles with potent antioxidant activity. The results indicate that silver nanoparticles, while capable of generating free radicals and interacting with cellular membranes, can also penetrate cells and induce reactive oxygen species (ROS) production. This intracellular ROS generation may lead to apoptosis (programmed cell death), membrane damage, and enzyme inhibition. The antioxidant activity of green-synthesized silver nanoparticles is primarily evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Comparative analyses reveal that silver nanoparticles synthesized using algae exhibit smaller particle sizes, while those synthesized with algae and plant extracts demonstrate higher antioxidant activity compared to other biological mediators. Silver nanoparticles (AgNPs) are well-known for their significant antioxidant properties due to their ability to scavenge and neutralize free radicals and reactive oxygen species (ROS). This characteristic has led to their widespread application in cosmetic, hygienic, and pharmaceutical products. Various synthesis approaches exist for producing silver nanoparticles, broadly categorized into top-down and bottom-up methods. The top-down approaches include mechanical activation, lithography, and other physical methods, whereas bottom-up approaches encompass hydrothermal synthesis, redox reactions, sol-gel processes, and green synthesis techniques. Among these, green synthesis has gained considerable attention because of its environmental friendliness, cost-effectiveness, and sustainability. Green synthesis utilizes natural sources such as plants, algae, fungi, and bacteria as reducing and stabilizing agents. This study aims to identify the most suitable green synthesis method for producing silver nanoparticles with potent antioxidant activity. The results indicate that silver nanoparticles, while capable of generating free radicals and interacting with cellular membranes, can also penetrate cells and induce reactive oxygen species (ROS) production. This intracellular ROS generation may lead to apoptosis (programmed cell death), membrane damage, and enzyme inhibition. The antioxidant activity of green-synthesized silver nanoparticles is primarily evaluated using the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay. Comparative analyses reveal that silver nanoparticles synthesized using algae exhibit smaller particle sizes, while those synthesized with algae and plant extracts demonstrate higher antioxidant activity compared to other biological mediators.

https://ceej.aut.ac.ir/article_5800_1dacb10f0623c67cb7dbb37587d8b38a.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Investigation of the Correlation between SPT Number, Shear Wave Velocity, and Small-Strain Shear Modulus in Northern Iran Investigation of the Correlation between SPT Number, Shear Wave Velocity, and Small-Strain Shear Modulus in Northern Iran 973 998 5802 10.22060/ceej.2025.23031.8094 FA Mohammad Hadi Hatefi Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran Mahyar Arabani Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran 0000-0002-4802-3725 Meghdad Payan Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran 0000-0002-1942-7915 Payam Zanganeh Ranjbar Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran Hassan Ahmadi Department of Civil Engineering, Faculty of Engineering, University of Guilan, Rasht, Iran Journal Article 2024 03 05 The shear wave velocity (Vs) and the small-strain shear modulus (Gmax) are crucial parameters to assess the dynamic properties of soil and the seismic characteristics of a site. In field trials, it may be challenging and costly to quantify these factors, limiting their feasibility. Thus, it is essential to determine indirectly Vs and Gmax using empirical equations linked to the SPT number. The present research focused on the seismic zone in the northern regions of Iran, where construction is rapidly increasing. The field tests were conducted by drilling eleven boreholes and analysing the correlation between SPT number, shear wave velocity, and small-strain shear modulus in clayey, sandy, and silty soil. The results were validated using data from three boreholes in a different area of northern Iran. Gmax is a parameter that reflects the dynamic characteristic of soils, specifically the hardness of geomaterials under shear deformation. Variations in the specific weight of soil layers affecting the small-strain shear modulus were analysed by correlating the SPT number to the small-strain shear modulus. The research findings demonstrated a strong correlation between the SPT number, shear wave velocity, and smallstrain shear modulus. Previous studies and data validation verified the models proposed in this research. Clayey soils are more sensitive to changes in the specific weight of each layer than sandy and silty soils. Since this sensitivity exhibits a non-linear relationship, it is crucial to consider the specific weight of each layer of soil when determining correlations for clayey soils. The shear wave velocity (Vs) and the small-strain shear modulus (Gmax) are crucial parameters to assess the dynamic properties of soil and the seismic characteristics of a site. In field trials, it may be challenging and costly to quantify these factors, limiting their feasibility. Thus, it is essential to determine indirectly Vs and Gmax using empirical equations linked to the SPT number. The present research focused on the seismic zone in the northern regions of Iran, where construction is rapidly increasing. The field tests were conducted by drilling eleven boreholes and analysing the correlation between SPT number, shear wave velocity, and small-strain shear modulus in clayey, sandy, and silty soil. The results were validated using data from three boreholes in a different area of northern Iran. Gmax is a parameter that reflects the dynamic characteristic of soils, specifically the hardness of geomaterials under shear deformation. Variations in the specific weight of soil layers affecting the small-strain shear modulus were analysed by correlating the SPT number to the small-strain shear modulus. The research findings demonstrated a strong correlation between the SPT number, shear wave velocity, and smallstrain shear modulus. Previous studies and data validation verified the models proposed in this research. Clayey soils are more sensitive to changes in the specific weight of each layer than sandy and silty soils. Since this sensitivity exhibits a non-linear relationship, it is crucial to consider the specific weight of each layer of soil when determining correlations for clayey soils.

https://ceej.aut.ac.ir/article_5802_077b83af57538aa183971a2fe0971ec1.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Numerical Modeling and Optimization of Rock Layers Arrangement to Reduce the Effect of Surface Impact Loading on Underground Spaces Numerical Modeling and Optimization of Rock Layers Arrangement to Reduce the Effect of Surface Impact Loading on Underground Spaces 999 1020 5809 10.22060/ceej.2025.19894.7322 FA Mohammad Yaser Radan Faculty Member of Passive Defense, Malek ashtar University of Technology Arian Tadrisi ParsaMoghadam Faculty of Passive Defense, Malek Ashtar University of Technology, Iran. Seyed Ahmad Hosseini Faculty Member of Passive Defense, Malek Ashtar University of Technology Journal Article 2021 05 11 Today, the use of buried spaces to protect sensitive facilities and equipment is not hidden from anyone. Buried safe spaces, especially tunnels, are used to create warehouses, maintain defense and military equipment, and also store some special materials and equipment. In addition, it is common to use these spaces as tunnels for urban services such as water transmission lines, telecommunications, energy, etc. Ensuring the security of these spaces against surface loads is one of the most important things in their construction and design. Buried spaces are exposed to various loadings, one of which is surface impact loading caused by an explosion. In this article, impact loading in buried environments is numerically modeled using the Eulerian-Lagrangian (CEL) method in the ABAQUS software environment. For this purpose, using single-layer, double-layer, and three-layer stone arrangements, the maximum pressure caused by impact load has been investigated in different models. According to the simulation results in this research, the highest amount of shock wave damping was obtained when the rock layer with the highest degree of weathering (porous rock) is located in the closest position to the buried space. Based on this, the safe depth of the modeled buried space was found to be about 12 meters for weak or porous rock, about 14 meters for medium rock, and about 18 meters for strong or pristine rock. Also, based on the results, the amount of transfer stress from weak rock to strong rock increases, and the amount of stress from strong rock to weak rock decreases. Today, the use of buried spaces to protect sensitive facilities and equipment is not hidden from anyone. Buried safe spaces, especially tunnels, are used to create warehouses, maintain defense and military equipment, and also store some special materials and equipment. In addition, it is common to use these spaces as tunnels for urban services such as water transmission lines, telecommunications, energy, etc. Ensuring the security of these spaces against surface loads is one of the most important things in their construction and design. Buried spaces are exposed to various loadings, one of which is surface impact loading caused by an explosion. In this article, impact loading in buried environments is numerically modeled using the Eulerian-Lagrangian (CEL) method in the ABAQUS software environment. For this purpose, using single-layer, double-layer, and three-layer stone arrangements, the maximum pressure caused by impact load has been investigated in different models. According to the simulation results in this research, the highest amount of shock wave damping was obtained when the rock layer with the highest degree of weathering (porous rock) is located in the closest position to the buried space. Based on this, the safe depth of the modeled buried space was found to be about 12 meters for weak or porous rock, about 14 meters for medium rock, and about 18 meters for strong or pristine rock. Also, based on the results, the amount of transfer stress from weak rock to strong rock increases, and the amount of stress from strong rock to weak rock decreases.

https://ceej.aut.ac.ir/article_5809_e68a83370faacfab07ae1f8aaf5352bb.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Evaluation of Flexural Strength Reduction Factors of Members in Reinforced Concrete Moment Frames Evaluation of Flexural Strength Reduction Factors of Members in Reinforced Concrete Moment Frames 1021 1046 5814 10.22060/ceej.2025.24032.8249 FA Naghmeh Haji Mohammad Yazdi Department of Civil and Environmental Engineering Siamak Epackachi Civil Engineering Department, Amirkabir University of Technology 0000-0001-9936-5517 Vahid Sadeghian Department of Civil and Environmental Engineering Ardeshir Deylami Department of Civil and Environmental Engineering Journal Article 2025 04 04 In this paper, the precise estimation of flexural resistance reduction factors in reinforced concrete beams and columns is investigated, considering the interaction effect of axial force for columns. To determine the reduction factors, 6,750 beams and 3,000 columns with various cross-sectional shapes, including rectangular, T-shaped, and L-shaped beams, as well as rectangular and circular columns, were examined. Different design variables, such as concrete compressive strength, reinforcement yield strength, reinforcement ratio, axial load ratio, and geometric dimensions, were considered for these sections. Random analyses were performed using the Latin hypercube sampling method with 1,000 samples for each section to account for uncertainties related to materials, geometry, and modeling. Additionally, statistical models of modeling uncertainty were updated using experimental data and analysis, and these updated models were employed. The proposed reduction factors for various conditions were calibrated based on reliability indices from the ASCE 7-22 code. The results indicate that, in many cases, particularly for transition and compression-controlled columns, the proposed factors are higher than the prescribed values in the ACI 318-19 code. This increase, especially in the design of gravity columns, can significantly reduce the weight of reinforcement and the volume of concrete (by approximately 40% and 15%, respectively, in an 8-story building), thereby considerably lowering construction costs while maintaining the required safety level. These findings highlight that updating the resistance reduction factors and utilizing variable values based on design characteristics can contribute to more economical and optimized structural designs. In this paper, the precise estimation of flexural resistance reduction factors in reinforced concrete beams and columns is investigated, considering the interaction effect of axial force for columns. To determine the reduction factors, 6,750 beams and 3,000 columns with various cross-sectional shapes, including rectangular, T-shaped, and L-shaped beams, as well as rectangular and circular columns, were examined. Different design variables, such as concrete compressive strength, reinforcement yield strength, reinforcement ratio, axial load ratio, and geometric dimensions, were considered for these sections. Random analyses were performed using the Latin hypercube sampling method with 1,000 samples for each section to account for uncertainties related to materials, geometry, and modeling. Additionally, statistical models of modeling uncertainty were updated using experimental data and analysis, and these updated models were employed. The proposed reduction factors for various conditions were calibrated based on reliability indices from the ASCE 7-22 code. The results indicate that, in many cases, particularly for transition and compression-controlled columns, the proposed factors are higher than the prescribed values in the ACI 318-19 code. This increase, especially in the design of gravity columns, can significantly reduce the weight of reinforcement and the volume of concrete (by approximately 40% and 15%, respectively, in an 8-story building), thereby considerably lowering construction costs while maintaining the required safety level. These findings highlight that updating the resistance reduction factors and utilizing variable values based on design characteristics can contribute to more economical and optimized structural designs.

https://ceej.aut.ac.ir/article_5814_f93486bfff38ca69d76d85c089569a09.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 The Effect of Nanographene and Nano Titanium Dioxide on the Mechanical Properties and Chloride Ion Penetration in Concrete The Effect of Nanographene and Nano Titanium Dioxide on the Mechanical Properties and Chloride Ion Penetration in Concrete 1047 1072 5815 10.22060/ceej.2025.24129.8261 FA Leila Shahryari Assistant Professor, Department of Civil Engineering, Shi.C., Islamic Azad University, Shiraz, Iran Mohamadamin Abedzadeh M.Sc. in Civil Engineering (Construction Engineering and Management), Faculty of Civil Engineering, Sharif University of Technology (Kish Campus), Kish, Iran Hossein Zarei Master's Degree, Department of Civil Engineering, Shi.C.,Islamic Azad University, Shiraz,Iran Journal Article 2025 05 05 Reinforced concrete marine structures located in coastal and corrosive environments are subjected to the attack of destructive chloride ions. In addition, sea waves and coastal storms impose significant stresses on the concrete, resulting in corrosion, abrasion, repeated cycles of wetting and drying, and chemical reactions involving chloride and sulfate ions. One of the main challenges for concrete structures near the shore is their high permeability to moisture and water, which leads to issues such as deterioration and cracking throughout the concrete. In particular, chloride and sulfate ions, which are among the primary causes of corrosion in reinforced concrete, can easily penetrate the structure due to high permeability and cause extensive damage. Therefore, it is essential to employ methods to minimize the permeability of concrete. In this study, with the aim of reducing concrete permeability and improving its durability against chloride ion penetration, a combination of nanographene and nano titanium dioxide was used in the concrete mix. The tests conducted in this study included slump, compressive strength at different ages, water absorption in hardened concrete, and durability against chloride ion penetration using the RCMT method. The results demonstrated that the use of the nanographene and nano titanium dioxide combination did not significantly affect the concrete slump, but the addition of nanographene negatively impacted the cement hydration reaction and reduced the compressive strength of the concrete. Specifically, the addition of 1.5% nanographene decreased the 90-day compressive strength by up to 22.5%. However, this amount of nanographene reduced the chloride ion penetration area in the concrete by up to 47%. Reinforced concrete marine structures located in coastal and corrosive environments are subjected to the attack of destructive chloride ions. In addition, sea waves and coastal storms impose significant stresses on the concrete, resulting in corrosion, abrasion, repeated cycles of wetting and drying, and chemical reactions involving chloride and sulfate ions. One of the main challenges for concrete structures near the shore is their high permeability to moisture and water, which leads to issues such as deterioration and cracking throughout the concrete. In particular, chloride and sulfate ions, which are among the primary causes of corrosion in reinforced concrete, can easily penetrate the structure due to high permeability and cause extensive damage. Therefore, it is essential to employ methods to minimize the permeability of concrete. In this study, with the aim of reducing concrete permeability and improving its durability against chloride ion penetration, a combination of nanographene and nano titanium dioxide was used in the concrete mix. The tests conducted in this study included slump, compressive strength at different ages, water absorption in hardened concrete, and durability against chloride ion penetration using the RCMT method. The results demonstrated that the use of the nanographene and nano titanium dioxide combination did not significantly affect the concrete slump, but the addition of nanographene negatively impacted the cement hydration reaction and reduced the compressive strength of the concrete. Specifically, the addition of 1.5% nanographene decreased the 90-day compressive strength by up to 22.5%. However, this amount of nanographene reduced the chloride ion penetration area in the concrete by up to 47%.

https://ceej.aut.ac.ir/article_5815_2835acf1b5aaa6ade0d10b4c977e912a.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Surface Coating with Advanced Nanocomposites: Photocatalytic Applications in the Degradation of Environmental Pollutants for Urban Environments Surface Coating with Advanced Nanocomposites: Photocatalytic Applications in the Degradation of Environmental Pollutants for Urban Environments 1073 1092 5817 10.22060/ceej.2025.23828.8223 FA Esmaeil Farmani Gheshlaghi Chemical Engineering Department, Amirkabir University of Technology, Tehran, Iran 0000-0001-5880-7788 Fariborz Rashidi Chemical Engineering Department, Amirkabir University of Technology, Tehran, Iran Majid Abdouss Chemistry Department, Amirkabir University of Technology, Tehran, Iran 0000-0003-2305-7985 Journal Article 2025 01 10 This study addresses the critical issue of air pollution in major metropolitan areas, including Tehran, and emphasizes the need for advanced surface coating technologies to reduce environmental contaminants in urban settings. The paper provides a comprehensive analysis of surface coating with advanced nanocomposites and their photocatalytic applications for the degradation of environmental pollutants. Nanocomposites composed of various materials, particularly semiconductor metal oxides such as TiO₂, ZnO, and g-C₃N₄, demonstrate high efficiency in decomposing micro-pollutants and atmospheric contaminants under light irradiation. Several coating techniques, including spray coating, electrophoretic deposition, and electrospinning, are reviewed, each offering distinct advantages depending on specific environmental conditions and surface requirements. Moreover, the integration of nanomaterials with emerging components such as graphene and MXenes enhances photocatalytic performance, corrosion resistance, and long-term stability of the coatings. Innovative synthesis techniques, such as plasma-based and electrochemical methods, also play a significant role in improving the efficiency of these coatings for air and water purification. Harnessing the photocatalytic properties of these materials using solar and other renewable energy sources, particularly in urban environments, offers a promising pathway for reducing air pollution and improving urban living standards. This study addresses the critical issue of air pollution in major metropolitan areas, including Tehran, and emphasizes the need for advanced surface coating technologies to reduce environmental contaminants in urban settings. The paper provides a comprehensive analysis of surface coating with advanced nanocomposites and their photocatalytic applications for the degradation of environmental pollutants. Nanocomposites composed of various materials, particularly semiconductor metal oxides such as TiO₂, ZnO, and g-C₃N₄, demonstrate high efficiency in decomposing micro-pollutants and atmospheric contaminants under light irradiation. Several coating techniques, including spray coating, electrophoretic deposition, and electrospinning, are reviewed, each offering distinct advantages depending on specific environmental conditions and surface requirements. Moreover, the integration of nanomaterials with emerging components such as graphene and MXenes enhances photocatalytic performance, corrosion resistance, and long-term stability of the coatings. Innovative synthesis techniques, such as plasma-based and electrochemical methods, also play a significant role in improving the efficiency of these coatings for air and water purification. Harnessing the photocatalytic properties of these materials using solar and other renewable energy sources, particularly in urban environments, offers a promising pathway for reducing air pollution and improving urban living standards.

https://ceej.aut.ac.ir/article_5817_d1588e685562af341ff2448de4b674d1.pdf

Amirkabir University of Technology Amirkabir Journal of Civil Engineering 2588-297X 57 6 2025 08 23 Improving Soil Surface Resistance and Stability Using EICP Process Improving Soil Surface Resistance and Stability Using EICP Process 1093 1110 5831 10.22060/ceej.2025.23283.8142 FA Sepideh Aghaalizadeh Department of Civil Engineering, K.N. Toosi University of Technology, Valiasr St., Mirdamad Cr., Tehran, Iran Farzin Kalantary Department of Civil Engineering, K.N. Toosi University of Technology, Valiasr St., Mirdamad Cr., Tehran, Iran Faezeh Ghanati Department of Plant Biology, Faculty of Biological Science, Tarbiat Modares University (TMU), Tehran, Iran Journal Article 2024 06 19 In recent years, soil surface erosion, especially by wind, has increased the area of deserts and increased problems for the ecosystem. Using biological methods to strengthen the soil's surface is a new way to prevent soil erosion. In this study, crude extract of soybean shoots has been used as a rich source of urease enzyme in the process of enzyme induced calcium carbonate precipitation (EICP). In this process, urea is hydrolyzed by urease enzyme and then the produced carbonate is combined with calcium in the EICP solution to produce calcium carbonate which acts as a binder for soil particles. The plant extract is a suitable substitute for pure urease enzyme or enzyme obtained by bacteria, which is costly to prepare. Three types of soils have been sprayed with EICP solution for biocementation using the EICP process and soil strength measurement test has been performed on the soil using a penetrometer. The thickness of the crust formed by the spraying of the solution has been measured. The results show that the method used increases the soil surface resistance and is a suitable method to prevent soil erosion. In recent years, soil surface erosion, especially by wind, has increased the area of deserts and increased problems for the ecosystem. Using biological methods to strengthen the soil's surface is a new way to prevent soil erosion. In this study, crude extract of soybean shoots has been used as a rich source of urease enzyme in the process of enzyme induced calcium carbonate precipitation (EICP). In this process, urea is hydrolyzed by urease enzyme and then the produced carbonate is combined with calcium in the EICP solution to produce calcium carbonate which acts as a binder for soil particles. The plant extract is a suitable substitute for pure urease enzyme or enzyme obtained by bacteria, which is costly to prepare. Three types of soils have been sprayed with EICP solution for biocementation using the EICP process and soil strength measurement test has been performed on the soil using a penetrometer. The thickness of the crust formed by the spraying of the solution has been measured. The results show that the method used increases the soil surface resistance and is a suitable method to prevent soil erosion.

https://ceej.aut.ac.ir/article_5831_228669109aa3ab1b4ec06b7722efb105.pdf